Which of the following words best replaces incredulous in the following excerpt?

"When did you come to New York?" he asked.

"I did not come to New York," I replied (while I added, mentally, "because I have been here for some time.")

"But you are in New York now," said the man.

"No," I said, looking as incredulous as I thought a crazy person could, "I did not come to New York."